Behavioural Ecology and Cognition of Chimpanzees

The vested interest in behaviour and cognition of chimpanzees is based on chimpanzees’ similarity to humans. Chimpanzees, and their sister species the bonobo (Pan paniscus), are our closest living relatives. Our evolutionary paths have diverted only about 7-8 million years ago. The evolutionary closeness makes chimpanzees an ideal model species to investigate behavioural and cognitive adaptations of humans, since they allow us a glimpse into the past of our own species.

The Taï Chimpanzees show a wide range of behaviours that appear to be very similar to that of humans. They use multiple tools to extract food, they cooperate during hunting of monkey prey and border patrols, they reconcile conflicts, they adopt orphans and they developed cultures. Although these behaviours are not unique features of Taï Chimpanzees, but can be found also in other chimpanzee populations, observations at TCP were either leading to the discovery or significantly contributed to our understanding of these behaviours. Much of the research on the Taï Chimpanzees has unravelled discoveries related to human evolution and animal cognition.

Here we use the possibilities that we can follow and observe four neighbouring communities of chimpanzees. Behavioural varaibility between neighbouring chimpanzee communities has likely no genetic nor environmnetal cause. Intergroup encounters can be observed from either side, allowing for the first time a possibility to observe behaviours of rival groups simultaniously when they meet.

Sociality and Health in Primates (SoHaPi)

Chronically elevated stress hormone levels can occur from repeated exposure to stressors, and can result in immuno-suppression, poor health and reduced longevity in humans and other social mammals. Social coping strategies can mitigate the deleterious effects of exposure, although little is known about the proximate mechanisms underlying such strategies, nor the impact of specific strategies on health. Two key coping strategies are often examined but rarely, if ever, contrasted in the same study, thus the relative impact of each on health and longevity is unclear. Social integration, where individuals maintain more central positions in a group, theoretically exposes individuals to stressors less frequently. In contrast, the social buffering effect of bond partners likely does not reduce the rate of exposure to stressors but might rather reduce the impact of each exposure. Whilst both should reduce the likelihood of chronic elevation of hypothalamic-pituitary-adrenal (HPA) activity, social buffering should in addition trigger oxytocin release, which has a regulatory effect on the HPA axis. Here, we will specifically contrast how usage of these two coping strategies over time relates to hormone and health measures, specifically measuring a non-specific immune-marker and virus load , in three communities of wild chimpanzees, in Taï National Park, Ivory Coast. This study allows us to investigate the relationship between different parameters of sociality and health including giving insights into the underlying mechanisms. These insights are likely to have broad applicability across social mammals, including for humans, particularly in understanding the impact of maintaining different social patterns on health.

Evolution of Brain Connectivity (EBC)

This project seeks to further our understanding of the brains of chimpanzees and other non-human primates, especially the communication, tool use and social cognition pathways. Using the comparative approach and our understanding of chimpanzee and monkey behavior, results will assist our understanding of similar structures and functions of the human brain, where until now, relatively little is known. Knowing similarities and differences in chimpanzee and human skills, comparisons between the chimpanzee and human brains will help us better understand the human brain. We aim particularly to examine parts of the brain that reflect differences in chimpanzee behavior with monkeys and chimpanzee behaviour with humans. Specifically, in comparison to most animals, chimpanzees have complex communication, social skills and too using abilities. Human skills, however, in all these dimensions are more sophisticated than those of chimpanzees. Parts of the brain have been described as functioning to support language (Broca’s area, Wernike’s area and white matter pathways such as the dorsal route), tool use (the parietal lobe) and social skills (the tempero-parietal lobe). We can compare these areas in chimpanzee, human and monkey brains to determine if structure in these areas fits expected extent usage of these areas per species.

Ape Attachment

Social bonding success in life impacts on health, survival and fitness. It is proposed that early and later social experience as well as heritable factors determine social bonding abilities in adulthood, although the relative influence of each is unclear. In humans, the resulting uncertainty likely impedes psychological and psychiatric assessment and therapy. One problem hampering progress for human studies is that social bonding success is hard to objectively quantify, particularly in adults. I propose to directly address this problem by determining the key influences on social bonding abilities in chimpanzees, our closest living relative, where social bonding success can be objectively quantified, and variation in underlying hormonal and cognitive mechanisms can be examined.

Chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are our closest living relatives. Although they share over 99% of DNA, their social systems show differences in relation tolerance, dominance, violence, and many other aspects. Understanding the underlaying mechanims of this difference and the ecological reasons helps to inform our understanding of the behaviour of the last common ancestor of human and Pan-species.